document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=580159>Question 580159</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Your fishing boat moves at 12 miles per hour relative to the surrounding water. You ride it from your house up the Mississippi River to a point that’s 16 miles distant, and then return to your house. The round trip takes 4 hours. The speed of the river is </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #371242 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=371242\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Your fishing boat moves at 12 miles per hour relative to the surrounding water.<BR>\n" );
document.write( " You ride it from your house up the Mississippi River to a point that’s 16 miles distant, and then return to your house.<BR>\n" );
document.write( " The round trip takes 4 hours. The speed of the river is<BR>\n" );
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document.write( "Let c = the speed of the river<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(12-c) = effective speed up-river<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(12+c) = effective speed down river<BR>\n" );
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document.write( "write a time equation; time = dist/speed<BR>\n" );
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document.write( "Upriver time + downriver time = 4 hrs<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=16%2F%28%2812-c%29%29 ALIGN=MIDDLE  ALT=\"16%2F%28%2812-c%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=16%2F%28%2812%2Bc%29%29 ALIGN=MIDDLE  ALT=\"16%2F%28%2812%2Bc%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 4<BR>\n" );
document.write( ";<BR>\n" );
document.write( "multiply by (12-c)(12+c), gets rid of the denominators and we have:<BR>\n" );
document.write( "16(12+c) + 16(12-c) = 4(12+c)(12-c)<BR>\n" );
document.write( ";<BR>\n" );
document.write( "192 + 16c + 192 - 16c = 4(144-c^2)<BR>\n" );
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document.write( "384 = 576 - 4c^2<BR>\n" );
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document.write( "4c^2 = 576 - 384<BR>\n" );
document.write( "4c^2 = 192<BR>\n" );
document.write( "c^2 = 192/4<BR>\n" );
document.write( "c^2 = 48<BR>\n" );
document.write( "c = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%2848%29 ALIGN=MIDDLE  ALT=\"sqrt%2848%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "c = 6.9282 ~ 6.9 mph is the speed of the river<BR>\n" );
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document.write( "See if that checks out<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=16%2F%28%2812-6.9%29%29 ALIGN=MIDDLE  ALT=\"16%2F%28%2812-6.9%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=16%2F%28%2812%2B6.9%29%29 ALIGN=MIDDLE  ALT=\"16%2F%28%2812%2B6.9%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "3.137 + .847 = 3.984 ~ 4 hrs </SPAN>\n" );
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